Filament coiling apparatus



April 20, 1948. PETERSEN 2,439,904

FILAMENT CO ILING APPARATUS Filed Aug. 1, 1945 .3; km? I Inventor; 36JUhUS Petersen,

by M.

' HIS Aftor'neg.

Patented Apr. 20, 1948 FILAMENT COILING APPARATUS Julius Petersen,Cleveland Heights, Ohio, assignor to General Electric Company, acorporation of New York Application August 1, 1945, Serial No. 608,257

11 Claims.

My invention relates, in general, to apparatus for coiling fine wireinto filaments for electric incandescent lamps and other similarelectrical devices, and more particularly to a gripper device forholding an end of the filament wire to be coiled.

In certain types of filament forming machines for the production ofcoiled lamp filaments having straight end legs extending laterally fromthe coil axis, the filament wire is fed transversely to and coiled on aforming mandrel. The free end of the filament wire is first positionedand held across the mandrel by a gripper device carried by the coilingspindle of the machine, and the mandrel and gripper are then rotated inunison to coil the filament wire around the mandrel.

The filament wire gripper heretofore in use on such type of filamentforming machines has comprised a slide member which isslidablelongitudinally of the mandrel and is provided with a thin lip orplate-like jaw portion which extends laterally of the mandrel and whichclamps the filament wire end or leg portion against a fiat surface onthe end of the coiling spindle. With such type grippers, the coilingspindle which carries the gripper can be rotated only through a numberof complete revolutions (i. e., no additional fraction of a revolutionis possible) since the gripper, in order to properly clamp the filamentwire at the start of each coiling cycle, must always be positioned inthe same rotative starting position. This requirement therefore limitsthe use of the machine insofar as concerns the production of differenttypes of filaments having difierent positioning of the filament legsangularly about the coil axis. Moreover, to permit the jaw of such typegrippers to be set as close as possible to the mandrel withoutinterfering with the first turn of the filament coil on the mandrel, thejaw was formed thin enough to enter the space between the leg portionand the first turn of the filament, which space is very small in thecase of filaments of incandescent lamps and similar devices. Since thegripper always had to be positioned in the same rotative startingposition, the filament wire was therefore engaged and clamped by thesame portion of the jaw gripping face during each filament coilingcycle, thus concentrating the wear on the jaw at one point. Because ofthe resultin excessive wear on the jaw and their relatively thinsection, such a law would either break or wear out in a relatively shortperiod of time thus necessitating its replacement from time to time.

One object of my invention is to provide an improved filament wiregripping device for filament coiling machines which will eflectivelygrip the filament wire in any rotative position of the coiling spindleon which the gripper is mounted.

Another object of my invention is to provide a filament wire grippingdevice the wear-undergoing parts of which are of sturdier constructionand much longer life than the corresponding parts of the grippingdevices heretofore in use.

Further objects and advantages of my invention will appear from thefollowing detailed description of a species thereof and from theaccompanying drawing, in which:

Fig. 1 is a fragmentary elevation of the coilin head of a filamentforming machine provided with a filament wire gripping device accordingto the invention; Fig. 2 is an enlarged plan view, partly in section, ofthe gripping device; and Fig. 3 is a section on the line 3-3 of Fig. 2.

Referring to the drawings, the filament wire gripper or chuck icomprising my invention is there shown as applied to the coiling head Aof a filament forming machine of the type wherein the filament wire isfed transversely to and coiled on a forming mandrel. Such a machine isdescribed and claimed in co-pending application Serial No. 608,115, FredB. Iden, filed of even date herewith. The coiling head A comprises ahollow spindle 2 extending through and journalled in a bearing 3 mountedon the table 4 of the machine. At its inner end, the coiling spindle 2carries the filament wire gripp r I and an axially extending mandrel 5on which the filament wire 6 is coiled. The mandrel 5, which normallyprojects outwardly beyond the nose of the gripper I, extends through thegripper and is held at its inner end in a mandrel chuck 1 carried by amandrel rod 8 reciprocable within the coiling spindle 2. During theoperation of the machine, the gripper and mandrel 5 are intermittentlyrotated in unison about the mandrel axis to thereby draw and wind thefilament wire 6 around the mandrel.

The gripper I according to the invention comprises inner and outersleeve members 9 and i0. respectively, which are longitudinally slidablerelative to one another. The inner end of the inner sleeve 9 projectsoutwardly beyond the corresponding end of the outer sleeve l0 and isprovided with a screw thread H which is screwed into a threaded socketl2 in the inner end of the coiling spindle 2 to thereby secure the innersleeve to the coiling spindle in coaxial alignment with one another. Atits outer end, the inner sleeve 8 carries a combination mandrel guidedie and inner jaw member I! in the form of a headed pin the stem portionll of which extends into 3 and fits snugly within the bore I5 of theinner sleeve while the head portion I6 of which overlies and abutsagainst the outer end of the inner sleeve. The mandrel guide pin I3 isprovided with an axially extending guide opening I I for receiving andguiding the mandreli. The outer face I8 of the head portion I6 of thepin is either in the form of a flat surface extending transversely ofthe mandrel 5, or a cone-shaped surface as shown, depending upon whetherthe filament legs are to extend from the filament coil in a direction atright angles. or other than at right angles to the axis of the filamentcoil. Th pin I3 and the inner sleeve 9 are rotatively locked together,as by a set screw I9 threaded into the inner sleeve and extending into akeyway 20 in the stem portion I4 of the pin.

At its outer end, the outer sleeve III is provided with a radiallyinturned annular flange or ring 2I which overlies the face I8 of the pinhead I6. The inner face 22 of the flange 2| is shaped to conform to theface I8 of the pin head I6 so as to form, together with the said faceI8, opposed annular jaw faces for gripping an end of the filament wiretherebetween. In the particular case illustrated, the gripping faces I8,22 are shown tapered at an angle of approximately 8 to conform to theapproximately 8 pitch angle of the particular filament coil which themachine, as shown in the drawings, is set up to form. The flange 2| iscontinuously urged towards the head I6 of pin I3, to thereby clamp thefree end portion of the filament wire 6 therebetween, by the force of acompression coil spring 23 fitting over the inner sleeve 9 andcompressed between an annular flange 24 extending radially outward fromthe outer end of the inner sleeve 9 and a retainer ring 25 disposedwithin and secured to the outer sleeve III. The flange 2| and the headI6 of the mandrel guide pin I3 thus constitute outer and inner annularjaw members, respectively, which are spring-pressed together to grip andhold the filament wire tightly therebetween, The inner and outer sleeves9 and I 0 are rotatively interlocked, so as to rotate in unison, by apin 26 fitting into aligned openings 21 and 28 located, respectively, inthe inner end of the outer sleeve and in an annular flange 29 whichextends radially outward from the inner sleeve and overlies the innerend of the outer sleeve. To permit assembly of the ring 25 and spring 23on the inner sleeve 9 between the flanges 24 and 29 thereon, theretainer ring is formed in two half-sections each one of which issecured to the outer sleeve III by a fastening screw 30 while the flange24 is provided with a diagonal slot 3I in its periphery through whichthe spring 23 is threaded.

During operation of the filament forming machine, the jaw portions I6and 2I of the chuck I are intermittently separated to allow insertion ofthe free end portion of the filament wire 6 through the central opening32 of flange 2I and into the space between the annular jaw faces I8, 22,and to subsequently release the said wire portion following the coilingoperation. The separation of the annular jaws I6, 2I is effected by acam-operated lever 33 pivotally mounted on the coiling spindle bearing3, and the insertion of the filament wire end into the separated jaws iseffected by the movement towards the mandrel of filament wire feed means38 operating in timed relation with the lever 33, as described in theabove mentioned co-pending application. The lever 33 is provided at oneend with spaced arms 34 which span the inner end of the coiling spindle4 2 and are provided with pins 35 for engagement with a radially outwardextending flange 36 on the outer sleeve III. When the lever 33 ispivoted in its chuck-opening direction, the pins 35 engage the flange 36and move the outer sleeve III forwardly relative to the inner sleeve 9,against the resistance of the spring 23, to thereby separate the jawfaces I8 and 22 of the chuck. When the lever 33 is pivoted in theopposite direction so as to disengage the pins 35 from the flange 36,the chuck spring 23 forces the outer sleeve I0 backwardly, thus closingthe chuck jaws I6 and 2| and clamping the end of the filament wiretightly between the jaw faces I8, 22. The lever 33 is normally held inits inoperative position out of engagement with the flange 36 of sleeveIII by a cam (not shown) mounted on the cam shaft of the machine, whileit is pivoted to its chuck-opening position by the expansive force of acompression coil spring 31 compressed between the lever and the spindlebearing 3. Obviously, to effect the opening of the chuck I, it isnecessary that the opening force applied to the outer sleeve III by thelever 33 and spring 31 be greater than the closing force exerted on thesaid sleeve III by the coil spring 23 within the chuck.

The provision of ring-shaped jaw surfaces I8, 22 surrounding the mandrel6 permits the filament leg to be gripped to start coiling at any pointon the complete 360 circle around the mandrel. Such feature permits adefinite improvement in coil quality and uniformity. By being able togrip the filament leg at any point around the circular extent of thechuck jaws I6 and 2|, it is possible to wind the required number of coilturns on the mandrel plus any fraction of a turn necessary to bring thelegs of the filament coil in proper relation to each other. Such featurealso permits the wear on the jaw faces I8, 22, incident to operatio ofthe machine, to be more or less uniformly distributed over the circularextent of the jaw faces by merely changing the rotative startingposition of the coiling spindle 2 at periodic intervals. Furthermore.the sturdier construction and longer life of the chuck jaw members I6and 2I, as compared to those heretofore in use, provides a considerablesaving in maintenance and parts replacement cost.

If desired, the combination mandrel guide die and jaw member I3 may beformed integral with the inner sleeve member 9. However, I prefer tomake it as a separate element in order to permit interchange thereofwith other die members having different sized mandrel guide openings I'Iand/or differently tapered wire gripping surfaces I8. Where the diemember I3 is replaced by one having a differently tapered grippingsurface I8, the outer sleeve I0 is also replaced by one having acorrespondingly tapered gripping surface 22. y selecting the properangle of taper of the gripping surfaces I8, 22, it is possible toproduce filaments having legs extending from the coil at an anglecorresponding to the pitch angle of the coil, which filamentconstruction is usually desirable.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A filament wire gripper for filament coiling apparatus comprisinginner and outer sleeve members slidable relative to one another, amandrel guide pin fitting within the hollow interior of and rotativelyinterlocked with the inner sleeve member. said pin having an axiallyextending man-drel guide opening and having its outer end locatedoutwardly beyond the outer end of the oearCfl KOOiTl inner sleeve memberand formed as an annular jaw face surrounding said opening, said outersleeve member being provided at its outer end with an inturned annularflange having an annular jaw face overlying and opposed to the jaw faceof said pin, and resilient means acting on one of said sleeve members toresiliently urge the opposed jaw faces together.

2. A filament wire gripper for filament coiling apparatus comprisinginner and outer sleeve members slidable relative to one another, aheaded pin rotatively interlocked with said inner sleeve member andhaving its stem portion extending into and fitting within the hollowinterior of the inner sleeve member and its head portion overlying andabutting against the outer end of the said inner sleeve member, said pinhaving an axially extending mandrel guide opening and having the outwardside of its head portion formed as an annular jaw face surrounding saidopening, said outer sleeve member being provided at its outer end withan inturned annular flange having an annular jaw face overlyingand-opposed to the jaw face of said p and resilient means acting on oneof said sleeve members to resiliently urge the opposed jaw facestogether.

3. A head for filament coiling apparatus comprising a coiling spindlehaving an axially extending mandrel guide opening at one end thereof,and a coiling mandrel extending axially of said spindle through saidguide opening and slidable therein to project outwardly beyond the saidspindle end, said spindle being provided at said end with a pair ofopposed annular jaw members surrounding said mandrel, said jaw membersbeing relatively movable axially of the spindle and resiliently urgedtowards one another to clamp an end of the filament wire therebetweenand hold it across the portion of the mandrel projecting outwardlybeyond the said spindle end.

4. A head for filament coiling apparatus comprising a coiling spindlehaving an axially extending mandrel guide opening at one end thereof, acoiling mandrel extending axiall of said spindle through said guideopening and slidable therein to project outwardly beyond the saidspindle end, a sleeve member surrounding the said end of the coilingspindle and provided with an inturned annular flange surrounding saidmandrel and overlying the said spindle end, said spindle being providedat said end with an annular jaw surface surrounding said mandrel andopposed to the said annular flange, and resilient means acting on saidsleeve member to resiliently urge the said flange thereof towards thesaid annular jaw surface to clamp an end of the filament wiretherebetween.

5. A filament wire gripper for filament coiling apparatus comprising asleeve member having an axially extending mandrel guide opening, acoiling mandrel extending axially of said sleeve through said guideopening and slidable therein to project outwardly beyond one end of saidsleeve, an annular jaw member surrounding said mandrel and opposed tothe said end of the sleeve, said sleeve being rotatively interlockedwith said jaw member and being provided at said end with an annular jawsurface surrounding said mandrel and facing said annular jaw member, andresilient means acting on said jaw member to resiliently urge it towardsthe said jaw surface to clamp an end of the filament wire therebetween,

6. A filament wire gripper for filament coiling apparatus comprisinginner and outer rotatively interlocked sleeve members slidable relativeto one another, said inner sleeve member having an axially extendingmandrel guide opening, a coiling mandrel extending axially of said innersleeve member through said guide opening and slidable therein to projectoutwardly beyond one end of said inner sleeve, said outer sleeve memberbeing provided at one end with an inturned annular flange surroundingsaid mandrel and having an annular jaw face opposed to the said end ofthe inner sleeve member, said inner sleeve member being provided at saidend with an annular jaw face surrounding said mandrel and facing the jawface of said outer sleeve member, and resilient means acting on one ofsaid sleeve members to resiliently urge the opposed jaw faces together.

7. A filament wire gripper for filament coiling apparatus comprisinginner and outer sleeve members slidable relative to one another, saidinner sleeve member having an axially extending mandrel guide opening, acoiling mandrel extending axially of said inner sleeve member throughsaid guide opening and slidable therein to project outwardly beyond oneend of said inner sleeve, said outer sleeve member being provided at oneend with an inturned annular flange surrounding said mandrel and havingan annular jaw face opposed to the said end of the inner sleeve member,said inner sleeve member being provided at said end with an annular jawface surrounding said mandrel and facing the jaw face of said outersleeve member, resilient means acting on one of said sleeve members toresiliently urge the opposed jaw faces together, and interengaging meanson said inner and outer sleeve members rotatively locking said memberstogether.

8. A filament wire gripper for filament coiling apparatus comprisinginner and outer rotatively interlocked sleeve members slidable relativeto one another, said inner sleeve member having an axially extendingmandrel guide opening, a coiling mandrel extending axially of said innersleeve member through said guide opening and slidable therein to projectoutwardly beyond one end of said inner sleeve, said outer sleeve memberbeing provided at one end with an inturned annular flange surroundingsaid mandrel and having an annular jaw face opposed to the said end ofthe inner sleeve member, said inner sleeve member being provided at saidend with an annular jaw face surrounding said mandrel and facing the jawface of said outer sleeve member, and a compression coil springcompressed between and acting on said sleeve members to resiliently urgethe opposed jaw faces together.

9. A filament wire gripper for filament coiling apparatus comprisinginner and outer rotatively interlocked sleeve members slidable relativeto one another, said inner sleeve member having an axially extendingmandrel guide opening, a coiling mandrel extending axially of said innersleeve member through said guide opening and slidable therein to projectoutwardly beyond one end of said inner sleeve, said outer sleeve memberbeing provided at one end with an inturned annular flange surroundingsaid mandrel and having an annular jaw face opposed to the said end ofthe inner sleeve member, said inner sleeve member being provided at saidend with an annular jaw face surrounding said mandrel and facing the jawface of said outer sleeve member, and a compression coil spring disposedwithin the outer sleeve member and fitting over the inner sleeve member,said coil spring being compressed between shoulders on said sleevemembers to resiliently urge the opposed jaw faces thereof together.

10. A filament wire gripper for filament coiling apparatus comprisingrotatively interlocked inner and outer sleeve members slidable relativeto one another and mounted on one end of a coiling spindle, said innersleeve member having an axially extending mandrel guide opening andbeing provided with an external collar adjacent its outer end, a coilingmandrel extending axially of said spindle through said guide opening andslidable therein to project outwardly beyond the outer end of said innersleeve member, said outer sleeve member being provided adjacent itsinner end with an internal collar and having at its outer end aninturned flange surrounding said mandrel and formed with an annular jawface overlying and opposed to the said outer end of the inner sleevemember, said inner sleeve member being provided at its outer end with anannular jaw face surrounding said mandrel and facing the jaw face ofsaid outer sleeve member, and a compression coil spring disposed withinthe outer sleeve member and fitting over the inner sleeve member andcompressed between the said collars on said sleeve members toresiliently urge the opposed jaw faces thereof together.

11. Filament coiling apparatus comprising, in combination, a coilingspindle having an axially extending mandrel guide opening at one end 8thereof, a coiling mandrel extending axially of said spindle throughsaid guide opening and slidable therein to project outwardly beyond thesaid spindle end, said spindle being provided at said end with a pair ofopposed rotatively-interlocked annular jaw members surrounding saidmandrel and relatively movable axially of the spindle, resilient meansnormally urging said jaw members together to clamp an end of thefilament wire therebetween and hold it across the portion of the mandrelprojecting outwardly beyond the said spindle end, jaw actuating meansengageable with one of said jaw members for moving it axially of thespindle and away from the other of said jaw members, and feed meansoperatively associated with said jaw actuating means and said jawmembers for inserting an end of the filament wire between the jawmembers when separated by said actuating means.

JULIUS PETERSEN.

REFERENCES CITED UNITED STATES PATENTS Name Date Jordan et al Nov. 1'7,1925 Number

